DESCRIPTION: Intestinal epithelial growth regulation has become an area of intense research interest. Part of the reason for this interest stems from the notion that a basic understanding of this process may have a tremendous impact on our ability to understand diseases such as cancer and inflammatory conditions which affect the digestive tract. In the intestine, cell division is confined to epithelial cells located near the base of the crypt. As cells migrate from the crypt, cell proliferation ceases and they differentiate into enterocytes which have to process and absorb nutrients from the gut lumen. The investigator has cloned a new gene (GKLF) which appears to be associated with the growth arrest phenotype. Three specific aims are proposed: a) examination of the structural-functional relationship of GKLF; b) determination of the effect of GKLF on cell growth; and c) analysis of the developmental expression pattern of GKLF in mice.